# US 12,120,479 B2 · Capacitance detection apparatus and earphone > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,120,479 B2 - Document ID: US12120479B2 - Status: Granted - Kind: B2 - Application number: 17/503,695 - Filed: 2021-10-18 - Published: 2022-09-22 - Granted: 2024-10-15 - Earliest claimed: 2021-03-19 - Assignees: Shenzhen Goodix Technology Co., Ltd. - Applicants: Shenzhen Goodix Technology Co., Ltd. - Inventors: Ming Yang; Zhe Chen - Web page: https://patentgrep.com/patent/US12120479B2 ## CPC - H04R 1/1041: {Mechanical or electronic switches, or control elements (switches in general H01H)} - H03K 17/962: {Capacitive touch switches} - H03K 2017/9602: {characterised by the type or shape of the sensing electrodes} - H03K 2217/960765: Details of shielding arrangements - H04R 1/1016: {Earpieces of the intra-aural type} - H04R 1/1058: {Manufacture or assembly} - H04R: LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; ELECTRIC HEARING AIDS; PUBLIC ADDRESS SYSTEMS (producing sounds with frequency not determined by supply frequency G10K) - H03K: PULSE TECHNIQUE (measuring pulse characteristics G01R; modulating sinusoidal oscillations with pulses H03C; transmission of digital information H04L; discriminator circuits detecting phase difference between two signals by counting or integrating cycles of oscillation H03D3/04; automatic control, starting, synchronisation or stabilisation of generators of electronic oscillations or pulses where the type of generator is irrelevant or unspecified H03L; coding, decoding or code conversion, in general H03M) ## Abstract A capacitance detection apparatus and earphone. The capacitance detection apparatus includes a front housing and a rear housing, where the capacitance detection apparatus includes: a circuit board, a sensing electrode and a processing unit which are provided at the front housing, where the circuit board, the sensing electrode and the processing unit are integrated together; the sensing electrode is arranged in a first area of the circuit board, the processing unit is arranged in a second area of the circuit board, and the sensing electrode and the processing unit are electrically connected through a metal wiring layer in the circuit board; the sensing electrode is configured to sense a to-be-measured object and form a capacitance detection signal, the capacitance detection signal is transmitted to the processing unit through the metal wiring layer, and the processing unit is configured to process the capacitance detection signal to detect the to-be-measured object. ## Claims ### Claim 1 A capacitance detection apparatus applied to an earphone, the earphone comprising a front housing and a rear housing, and the capacitance detection apparatus comprises: a circuit board, a sensing electrode and a processing unit which are provided at the front housing of the earphone, wherein the circuit board, the sensing electrode and the processing unit are integrated together; wherein the sensing electrode is arranged in a first area of the circuit board, the processing unit is arranged in a second area of the circuit board, and the sensing electrode and the processing unit are electrically connected through a metal wiring layer in the circuit board; the sensing electrode is configured to sense a to-be-measured object and form a capacitance detection signal, the capacitance detection signal is transmitted to the processing unit through the metal wiring layer, and the processing unit is configured to process the capacitance detection signal to detect the to-be-measured object; wherein the circuit board is a flexible circuit board, and the capacitance detection apparatus further comprises: a temperature drift compensator, provided on the flexible circuit board and configured to compensate for a temperature drift of the capacitance detection signal of the sensing electrode on the flexible circuit board. ### Claim 2 (depends on 1) The capacitance detection apparatus according to claim 1, wherein the sensing electrode and the processing unit are respectively arranged on a first surface and a second surface of the circuit board, wherein the first surface is a surface of the circuit board facing the to-be-measured object, and the second surface is a surface of the circuit board facing away from the to-be-measured object. ### Claim 3 (depends on 1) The capacitance detection apparatus according to claim 1, wherein the temperature drift compensator comprises: a reference electrode arranged in a third area of the circuit board and configured to form a reference capacitance detection signal, wherein the reference electrode and the processing unit are electrically connected through the metal wiring layer in the circuit board; the reference capacitance detection signal of the reference electrode is configured to compensate for the temperature drift of the capacitance detection signal of the sensing electrode. ### Claim 4 (depends on 3) The capacitance detection apparatus according to claim 3, wherein the reference electrode is arranged on a side of the sensing electrode away from the to-be-measured object, and the sensing electrode covers the reference electrode. ### Claim 5 (depends on 4) The capacitance detection apparatus according to claim 4, wherein in a first period, the sensing electrode is configured to sense the to-be-measured object and form the capacitance detection signal; and in a second period, the reference electrode is configured to form the reference capacitance detection signal, and the sensing electrode is configured to receive a shielding signal to shield influence of the to-be-measured object on the reference capacitance detection signal of the reference electrode, wherein the shielding signal comprises: a ground signal, a direct current signal, or a signal with a same frequency and phase as the reference capacitance detection signal. ### Claim 6 (depends on 5) The capacitance detection apparatus according to claim 5, wherein in the first period, the reference electrode is configured to receive a ground signal or a direct current signal to prevent the reference electrode from influencing the capacitance detection signal of the sensing electrode. ### Claim 7 (depends on 3) The capacitance detection apparatus according to claim 3, wherein the sensing electrode is arranged on the first surface of the circuit board, the processing unit and the reference electrode are arranged on the second surface of the circuit board, wherein the first surface is a surface of the circuit board facing the to-be-measured object, and the second surface is a surface of the circuit board facing away from the to-be-measured object. ### Claim 8 (depends on 7) The capacitance detection apparatus according to claim 7, wherein the reference electrode and the sensing electrode have a same shape and size, and the reference electrode and the sensing electrode are arranged symmetrically with respect to the circuit board. ### Claim 9 (depends on 3) The capacitance detection apparatus according to claim 3, wherein the circuit board comprises: a first partial circuit board, a bending portion, and a second partial circuit board, wherein the first partial circuit board and the second partial circuit board are stacked and connected with each other through the bending portion; and the sensing electrode and the reference electrode are arranged on the first partial circuit board, the processing unit is arranged on the second partial circuit board, and the first partial circuit board is arranged toward the to-be-measured object relative to the second partial circuit board. ### Claim 10 (depends on 9) The capacitance detection apparatus according to claim 9, wherein the sensing electrode and the reference electrode are respectively arranged on a first surface and a second surface of the first partial circuit board, and the processing unit is arranged on a second surface of the second partial circuit board, wherein the first surface is a surface of the first partial circuit board and the second partial circuit board facing the to-be-measured object, and the second surface is a surface of the first partial circuit board and the second partial circuit board facing away from the to-be-measured object. ### Claim 11 (depends on 10) The capacitance detection apparatus according to claim 10, wherein the reference electrode and the sensing electrode have a same shape and size, and the reference electrode and the sensing electrode are arranged symmetrically with respect to the first partial circuit board. ### Claim 12 (depends on 1) The capacitance detection apparatus according to claim 1, wherein the temperature drift compensator comprises: a temperature sensor integrated in the processing unit, and a temperature signal of the temperature sensor is configured to compensate for the temperature drift of the capacitance detection signal of the sensing electrode. ### Claim 13 (depends on 1) The capacitance detection apparatus according to claim 1, wherein the processing unit is further configured to process an external capacitance detection signal of an external electrode, and an antenna in the earphone is reused as the external electrode. ### Claim 14 (depends on 13) The capacitance detection apparatus according to claim 13, wherein the processing unit is configured to process the capacitance detection signal of the sensing electrode to detect a proximity state of the to-be-measured object; and the processing unit is configured to process the external capacitance detection signal of the external electrode to detect a touch state of the to-be-measured object. ### Claim 15 (depends on 1) The capacitance detection apparatus according to claim 1, wherein the capacitance detection signal of the sensing electrode is a capacitance detection signal of a self-capacitance between the sensing electrode and a ground electrode; or the capacitance detection signal of the sensing electrode is a capacitance detection signal of a mutual capacitance between the sensing electrode and its corresponding transmitting electrode. ### Claim 16 (depends on 1) The capacitance detection apparatus according to claim 1, wherein the circuit board is a flexible circuit board, and the capacitance detection apparatus further comprises: a reinforcing plate, configured to reinforce an area of the flexible circuit board corresponding to the processing unit. ### Claim 17 (depends on 1) The capacitance detection apparatus according to claim 1, wherein the capacitance detection apparatus is fixedly mounted to the front housing of the earphone by an adhesive layer. ### Claim 18 (depends on 1) The capacitance detection apparatus according to claim 1, wherein the processing unit is configured to process the capacitance detection signal to form a digital signal, and the capacitance detection apparatus and a main board of the earphone are electrically connected by a digital signal line, and the main board of the earphone is arranged at the rear housing of the earphone. ### Claim 19 (depends on 1) The capacitance detection apparatus according to claim 1, wherein the sensing electrode comprises an electrode pattern, and the electrode pattern is formed on a metal layer on a surface of the circuit board. ### Claim 20 An earphone, comprising: a capacitance detection apparatus, a front housing, and a rear housing, wherein the capacitance detection apparatus comprises: a circuit board, a sensing electrode, and a processing unit which are provided at the front housing of the earphone, wherein the circuit board, the sensing electrode and the processing unit are integrated together; wherein the sensing electrode is arranged in a first area of the circuit board, the processing unit is arranged in a second area of the circuit board, and the sensing electrode and the processing unit are electrically connected through a metal wiring layer in the circuit board; and the sensing electrode is configured to sense a to-be-measured object and form a capacitance detection signal, the capacitance detection signal is transmitted to the processing unit through the metal wiring layer, and the processing unit is configured to process the capacitance detection signal to detect the to-be-measured object; wherein the circuit board is a flexible circuit board, and the capacitance detection apparatus further comprises: a temperature drift compensator, provided on the flexible circuit board and configured to compensate for a temperature drift of the capacitance detection signal of the sensing electrode on the flexible circuit board.